C) the Cuban government became more closely aligned with Soviet Union
Explanation:
The disastrous American invasion of the Bay of Pigs in Cuba began on April 17, 1961. The Bay of Pigs is a sea bay on the southern coast of Cuba. The US plan was to land Cuban emigrants trained by the CIA for war there, after which they should launch a civil war and overthrow Castro's power in Cuba.
Specifically, US-Cuban tensions began when Castro overthrew General Batista's regime on January 1, 1959. The US administration estimated that Castro was increasingly turning to the Communists, and they could not tolerate it in their neighborhood. About 1,400 emigrants were landed.
The Cubans resisted the invasion, including the famous Che Guevara, and in just three days managed to completely defeat the invaders. For Americans, it was a great defeat and a national embarrassment, and the result was Castro's complete turn to the USSR.
A slave is a person that belongs to another one and is treated as property. Serfs, I'm not so sure about this now, were renting the land out from the landowners.
